Apparatus for charging a solid propellant mix with metallic fibers

ABSTRACT

1. AN APPARATUS FOR CHARGING A SOLID PROPELLANT MIX, COMPRISING AN OPEN-END HOUSING THAT IS ADAPTED TO BE POSITIONED ON THE OPEN THROAT OF A MIXER FOR THE MIX, SAID HOUSING INCLUDING A BASE PLATE HAVING AN OPENING THEREIN CONFORMING TO THE OPEN THROAT OF THE MIXER, A PAIR OF SPACED PARALLEL DIVERGING RECTANGULAR-SHAPED DEFLECTORS SECURED TO SAID BASE PLATE WITHIN SAID HOUSING AND WITH THE LOWER LONGITUDINAL EDGES THEREOF EXTENDING THROUGH THE OPENING IN SAID BASE PLATE, A ROTARY DRUM COMPRISING A PAIR OF DISC-SHAPED END PLATES AND A RETICULATED AND CIRCULAR WALL SECURED AT ITS OPPOSITE EDGES TO THE PERIPHERAL EDGES OF SAID END PLATES, DIAMETRICALLY OPPOSED BEARING PLATES SECURED TO THE OUTER SURFACE OF SAID HOUSING, A SHAFT EXTENDING THROUGH SAID BEARING PLATES, SAID HOUSING AND SAID END PLATES CENTRALLY THEREOF AND LONGITUDINALLY OF SAID DRUM FOR ROTATABLY MOUNTING SAID DRUM WITHIN SAID HOUSING TRANSVERSELY THEREOF, AN ELECTRIC MOTOR HAVING A GEAR TRAIN SECURED THERETO MOUNTED ON SAID BASE PLATE SO THAT A FLEXIBLE OPERATIONAL COUPLING BETWEEN SAID GEAR TRAIN AND A PULLEY ON SAID SHAFT OUTWARDLY OF ONE OF SAID BEAR ING PLATES WILL CAUSE SAID DRUM TO BE ROTATED AT A CONSTANT AND EVEN RATE OF SPEED, A PLURALITY OF EQUALLY-SPACED, RECTANGULAR-SHAPED BAFFLES, EACH BAFFLE HAVING THE INNER LONGITUDINAL PORTION THEREOF LATERALLY INCLINED IN RELATION TO THE MAIN LONGITUDINAL PORTION WITH THE OUTER LONGITUDINAL EDGE THEREOF SECURED TO SAID WALL, AN ACCESS DOOR HINGEDLY MOUNTED IN SAID WALL AND FASTENERS MOUNTED ON SAID ACCESS DOOR AND SAID WALL FOR ERETAINING SAID ACCESS DOOR IN CLOSED POSITION.

March 2, 1971 COOPER ETAL 3,567,188

APPARATUS FOR CHARGING A SOLID PROPELLANT MIX WITH METALLIC FIBERS Filed Jan. 9, 1964 I5 Sheets-Sheet 1 Marvin H. Cooper James C. Miller INVENTORS Walter E. Buckner ATTORNEY March 2, 1971 COOPER' ETAL 3,567,188

APPARATUS FOR CHARGING A SOLID PROPELLAN'I MIX WITH METALLIC FIBERS 3 Sheets-Sheet 3 Filed Jan. 9., 1964 Marvin H. Cooper James C. Miller INVENTORS Walter E. Buckner AT TORNE Y March 2, 1971 COOPER EIAL 3,567,188

' APPARATUS FOR CHARGING A SOLID PROPELLANT MIX WITH METALLIC FIBERS Filed Jan. 9, 1964 S'SheetS-Sheet 5 Marvlh H. Cooper I James C. Miller INVENTORS Walter E. Buckner AT TORNE Y.

United States Patent Ofifice 3,567,188 APPARATUS FOR CHARGING A SOLID PROPELLANT MIX WITH METALLIC FIBERS Marvin H. Cooper, James C. Miller, and Walter E. Buckner, Huntsville, Ala., assignors to Thiokol Chemical Corporation, Bristol, Pa.

Filed Jan. 9, 1964, Ser. No. 336,837

, Int. Cl. B01f 3/18 US. Cl. 259--3 1 Claim This invention relates to improvements in an apparatus for charging a viscous mix with metallic fibers and, more particularly, to an apparatus that will charge a solid propellant mix with a predetermined amount of metallic fibers that are distributed thereby into the solid propellant mix at an even and constant rate.

Developments in solid propellants in the past have shown that the high-energy, fast-burning solid propellants that will he demanded for forthcoming missile systems may be produced by adding a mechanical, high-burning rate catalyst, such as metallic fibers, to an existing and conventional solid propellant formulation. While it is a well-known fact that a high-burning rate may be attained through chemical catalysts, these materials tend to hypersensitize solid propellant, whereas the addition of mechanical burning rate catalysts do not.

However, the greatest problem to overcome is the addition of the mechanical burning rate catalysts to a solid propellant mix. If the mechanical burning rate catalysts are not fed into the solid propellant mix at an even and constant rate, the mechanical burning rate catalysts will not be distributed through the solid propellant in a somewhat orderly fashion but will tend to be fed into the solid propellant in tangled masses which will result in uneven dispersion within the solid propellant mix.

Since it has been determined that an even dispersion of the mechanical burning rate catalysts throughout the propellant would result in more consistent burning characteristics or better ballistic reproducibility, some means whereby an even dispersion of the mechanical burning rate catalysts had to be achieved.

It is an object of this invention, therefore, to provide an apparatus that will properly charge a solid propellant mix with a mechanical burning rate catalyst so that the mechanical burning rate catalyst is evenly dispersed in the solid propellant mix resulting in increased homogeneity of the finished propellant.

Preliminary process studies conducted with several types of mechanical burning rate catalysts immediately indicated that the addition of a significant quantity of such a material to a large amount of solid propellant could not be successfully obtained with any available apparatus, and the use of such apparatus would be impractical. It became apparent, therefore, that some type of apparatus would have to be developed whereby the mechanical burning rate catalysts could be added safely and rapidly and that the apparatus would be susceptible of being operated at a remote location with regards to an operating solid propellant mixer.

It is another object of this invention, therefore, to provide an apparatus that will charge a solid propellant mix at an even and constant rate while it is able to simultaneously maintain from a remote location a high degree of control over the charging process.

When the mechanical burning rate catalyst consisted of metallic fibers, it was found that such fibers would have a tendency to bird nest, and thus be incorporated in this state into the solid propellant mix at undetermined locations. Since such a distribution would not give the desired result, it became apparent that some method of adding the metallic fibers would have to be achieved to 3,567,188 Patented Mar. 2, 1971 eliminate this disadvantage if the addition of the metallic fibers were to result in a high-burning rate solid propellant.

The present apparatus, which involves a simple screening system that could be properly controlled with sufficient reliability, safety, and practicality, was, therefore, developed.

A further object of this invention, therefore, is to provide an apparatus that would feed metallic fibers into a solid propellant mix, so that the metallic fibers were no larger than the clearances of the mixer blades, thus eliminating, to a great extent, static electricity, and distribution of the metallic fibers over the surface of the solid propellent mix in a somewhat even dispersion in the proper amount at a constant rate so that the solid propellant mix will meet prescribed specifications.

Therefore, since the metallic fibers will not be fed in masses and there would be no danger of the fibers being pinched between the mixer blades, danger of ignition by static electricity would be eliminated. Thus a low degree of static electricity and no masses of metallic fibers are safety advantages inherent in the present invention.

With the above and other objects and advantages in view, the invention consists of the novel details of construction, arrangement, and combination of parts more fully hereinafter described, claimed, and illustrated in the accompanying drawings in which:

FIG. 1 is a perspective view, partly broken away, to more clearly disclose the apparatus forming an embodiment of the present invention.

FIG. 2 is a perspective view of the rotary drum of the apparatus with the housing therefor outlined in dotted mes.

FIG. 3 is a transverse, sectional view of the rotary drum, and

FIG. 4 is a vertical, sectional view of the rotary drum on the line 44 of FIG. 3.

Referring more in detail to the drawings wherein like parts are designated by like reference numerals, the reference numeral 10 is used to generally designate the apparatus embodying the invention.

The apparatus 10 comprises a substantially rectangular-shaped base plate 11 which is of a size to conform with the open throat of a conventional solid propellant mixer 12. A feeding trough 13 of conventional design is positioned above the apparatus 10 so that metallic fibers of predetermined sizes may be continuously delivered into the open top 14 of the apparatus 10.

An open-ended, substantially-rectangular-shaped housing 15 is secured to the base plate 11 in equally-spaced relation to the edges thereof; and the base plate 11 is provided with a centrally-located opening 16 that is contiguous with the lower peripheral edges of the housing 15. Secured at their opposite ends to the base plate 11 within the confinement of the opening 16 in diverging relation to each other are a pair of substantially rectangular-shaped deflector plates 17 and 18 respectively; and the deflector plates 17 and 18 extend in spacedparallel relation to each other transversely of the housing 15. The lower longitudinal edges thereof extend over and inwardly of the portions of the base plate 11 defining the opening 16, and the upper longitudinal edges thereof are rigidly secured to the inner surface of the walls of the housing 15 with which they are parallel.

Vertically-disposed, substantially rectangular-shaped bearing plates 19 are secured in diametrically-opposed relation to each other to the outer surfaces of the walls of the housing 15 that extend at right angles to the deflectors 17 and 18; and a shaft 20 of a rotary drum 21 is journaled at its opposite ends in the bearing plates 19.

An electric motor 22 is mounted on the base plate 11 outwardly of the housing 15 adjacent to the wall of the housing 15 and one of the bearing plates 19 secured thereto. A gear train 23 mounted in a support 24 secured to the lower end of the bearing plate 19 adjacent to the electric motor 22 has an operational coupling with the electric motor 22, and a pulley 25 on the drive shaft of the gear train 23 has a flexible drive connection 26 with a pulley 27 secured to the outer end of the shaft of the rotary drum 21. A bearing and pulley-retaining arm 28 positioned outwardly of the pulley 27 and secured to the bearing plate 19 vertically of and in spaced relation to the pulley serves to additionally support the outer end of the shaft 20 and prevents the pulley 27 from becoming disconnected from the shaft 20.

The rotary drum 21 consists of a pair of spaced discshaped end plates 29 and 30 respectively; and extending therebetween and rigidly secured thereto at their outer ends in equallyspaced parallel relation to each other are a plurality of baffles 31. At the outer free longitudinal edges thereof, the baflles 31 are angled to the left of the transverse axis thereof, as shown at 32. The outer circular wall of the rotary drum 21 is made of a reticulated material 33 which is rigidly secured at its opposite peripheral edges to the peripheral edges of the end plates 29 and 30 and to the inner longitudinal edges of the baflies 31. An access door 34 of the same material 33 is hinged at 35 along one longitudinal edge thereof to one of the bafiles 31, and trunk fasteners 36 mounted on the free longitudinal edge of the access door 34 and the material defining the space occupied by the access door 34 serve to retain the access door 34 in closed position.

The instant invention was designed to charge a solid propellant mix with metallic fibers which are fed to the hopper 13 for distribution to the rotary drum 21 of the apparatus 10 when the access door 34 in the rotary drum 21 is open to receive such distribution and the rotary drum 21 is stationary. When a predetermined amount of the metallic fibers has been received in the rotary drum 31, the access door 34 is closed and the electric motor 22 is energized. The gear train 23 will then be activated, and the rotary drum 21 will rotate at a constant predetermined speed. Thus, the metallic fibers will be fed evenly and at a constant rate of speed into the mixer 12. The metallic fibers will thus fall by gravity onto the surface of the solid propellant mix and be incorporated therein so that the resultant mix will meet specifications. The deflectors 17 and 18 cause the metallic fibers to fall clear of the open throat of the mixer 12 so that they will not adhere to the throat and bunch up to cause erratic distribution of the metallic fibers onto the surface of the solid propellant mix.

The size of the apparatus 10 may be varied to conform to mixers of various sizes, and the reticulated material forming the circular wall of the rotary drum 21 may also be varied to conform to the different sizes of the metallic fibers that are necessary to be used. However, it is believed that, from the foregoing description, the structure and manner of operation of the apparatus will be clear to those skilled in the art. It also being understood that variations in the manner of constructing the apparatus may be adhered to providing such variations fall within the spirit of the invention and the scope of the'appended claim.

Having thus described the invention, what is claimed as new and desired to be secured by letters patent is:

1. An apparatus for charging a solid propellant mix, comprising an open-end housing that is adapted to be positioned on the open throat of a mixer for the mix, said housing including a base plate having an opening therein conforming to the open throat of the mixer, a pair of spaced parallel diverging rectangular-shaped deflectors secured to said base plate within said housing and with the lower longitudinal edges thereof extending through the opening in said base plate, a rotary drum comprising a pair of disc-shaped end plates and a reticulated and circular wall secured at its opposite edges to the peripheral edges of said end plates, diametrically opposed bearing plates secured to the outer surface of said housing, a shaft extending through said bearing plates, said housing and said end plates centrally thereof and longitudinally of said drum for rotatably mounting said drum within said housing transversely thereof, an electric motor having a gear train secured thereto mounted on said base plate so that a flexible operational coupling between said gear train and a pulley on said shaft outwardly of one of said bearing plates will cause said drum to be rotated at a constant and even rate of speed, a plurality of equally-spaced, rectangular-shaped bafiles, each bafile having the inner longitudinal portion thereof laterally inclined in relation to the main longitudinal portion with the outer longitudinal edge thereof secured to said wall, an access door hingedly mounted in said wall and fasteners mounted on said access door and said wall for retaining said access door in closed position.

References Cited UNITED STATES PATENTS 224,341 2/ 1880 Koplin 209-286 1,438,861 12/ 1922 Root 209-294 1,613,553 1/1927 Arthur 209-284 2,588,592 3/1952 Trundle 209-284 148,202 3/ 1874 Fuller 209-284 514,261 2/1894 Christie 209-286 ROBERT F. STAHL, Primary Examiner US. Cl. X.R. 209-284 

1. AN APPARATUS FOR CHARGING A SOLID PROPELLANT MIX, COMPRISING AN OPEN-END HOUSING THAT IS ADAPTED TO BE POSITIONED ON THE OPEN THROAT OF A MIXER FOR THE MIX, SAID HOUSING INCLUDING A BASE PLATE HAVING AN OPENING THEREIN CONFORMING TO THE OPEN THROAT OF THE MIXER, A PAIR OF SPACED PARALLEL DIVERGING RECTANGULAR-SHAPED DEFLECTORS SECURED TO SAID BASE PLATE WITHIN SAID HOUSING AND WITH THE LOWER LONGITUDINAL EDGES THEREOF EXTENDING THROUGH THE OPENING IN SAID BASE PLATE, A ROTARY DRUM COMPRISING A PAIR OF DISC-SHAPED END PLATES AND A RETICULATED AND CIRCULAR WALL SECURED AT ITS OPPOSITE EDGES TO THE PERIPHERAL EDGES OF SAID END PLATES, DIAMETRICALLY OPPOSED BEARING PLATES SECURED TO THE OUTER SURFACE OF SAID HOUSING, A SHAFT EXTENDING THROUGH SAID BEARING PLATES, SAID HOUSING AND SAID END PLATES CENTRALLY THEREOF AND LONGITUDINALLY OF SAID DRUM FOR ROTATABLY MOUNTING SAID DRUM WITHIN SAID HOUSING TRANSVERSELY THEREOF, AN ELECTRIC MOTOR HAVING A GEAR TRAIN SECURED THERETO MOUNTED ON SAID BASE PLATE SO THAT A FLEXIBLE OPERATIONAL COUPLING BETWEEN SAID GEAR TRAIN AND A PULLEY ON SAID SHAFT OUTWARDLY OF ONE OF SAID BEAR ING PLATES WILL CAUSE SAID DRUM TO BE ROTATED AT A CONSTANT AND EVEN RATE OF SPEED, A PLURALITY OF EQUALLY-SPACED, RECTANGULAR-SHAPED BAFFLES, EACH BAFFLE HAVING THE INNER LONGITUDINAL PORTION THEREOF LATERALLY INCLINED IN RELATION TO THE MAIN LONGITUDINAL PORTION WITH THE OUTER LONGITUDINAL EDGE THEREOF SECURED TO SAID WALL, AN ACCESS DOOR HINGEDLY MOUNTED IN SAID WALL AND FASTENERS MOUNTED ON SAID ACCESS DOOR AND SAID WALL FOR ERETAINING SAID ACCESS DOOR IN CLOSED POSITION. 